EXHAUST PROCESS OF INTERNAL CONBUTION ENGINE

PURPOSE:To decrease exhaust working, by connecting an main exhaust pipe of a four cycle engine having an exhaust gas supercharger to a high pressure exhaust pipe during high pressure exhaust and connecting the exhaust pipe to a low pressure exhaust pipe after high pressure exhaust. CONSTITUTION:An exhaust pipe is systematized in two systems of a high pressure exhaust pipe 10 and a low pressure exhaust pipe 9, and these systems are connected to a main exhaust pipe 11 through a high pressure exhaust valve 8 and a low pressure exhaust valve 7. At the end in explosion stroke, an exhaust valve 4 and the high pressure exhaust valve 8 are opened and the low pressure exhaust valve 7 is closed. And in the early stage of exhaust stroke and intake stroke, the exhaust valve 4 and the low pressure exhaust valve 7 are opened and the high pressure exhaust valve 8 is closed. Thereby pressure in a combustion cylinder is lowered than former method and exhaust working is deceased during exhaust stroke, and power of driving shaft is increased so that fuel consumption rate can be improved.